It is proven in murine models and generally accepted in humans that the immune system must play a role in resistance to the growth and spread of neoplasms. The objectives of our research are to investigate the role of cellular immunity and the HLA complex in the biology of human bladder carcinoma. Recent studies in murine and human models suggest that the major histocompatibility complex (H2 in the mouse, and HLA in humans) plays a central role in immune function. We propose: 1) to continue our studies on the question of whether bladder cancer patients have tumor-induced (triggered) suppressor cells circulating in their blood in order to confirm and extend our observations that suggest they do; 2) to continue our studies on a patient with bladder cancer who has allo-restricted (anti-B14) suppressor T-cells in order to further characterize those cells, their function, and to determine whether other bladder cancer patients have such allo-restricted suppressor T-cells; and 3) to continue our study of the relationship of the HLA complex antigens with the incidence, type, and course of disease in patients with bladder carcinoma in order to confirm or refute preliminary findings of an excess of HLA-DR4 in bladder cancer patients and to examine for any unique association of these HLA complex antigens with the various types of bladder carcinoma and with disease outcome.